Controlled needle tufting machine

ABSTRACT

An adjustable needle stroke controlled needle tufting machine having means for selectively reciprocating the needles individually between an inoperative and operative position to produce patterned fabric. The machine is provided with mechanisms so that a large variation in pile height fabrics can be produced with the same machine without necessitating a complete machine conversion. The mechanism for accomplishing this comprises an adjustable needle plate, and adjustable needle stroke mechanism including an adjustable needle stop to limit the upward stroke of the needle carrier in the inoperative position.

United States Patent [111 3,881,432

Dodd et al. 1 May 6, 1975 [54] CONTROLLED NEEDLE TUFTING 3,386,403 6/1968 Short 112/79 R X MACHINE 3,830,174 8/1974 Mellon 112/79 R Inventors: Connie W. Dodd, Chattanooga;

William D. Stone, East Ridge, both Appl. No.: 479,021

Primary ExaminerWerner H. Schroeder Attorney, Agent, or FirmMarshall J. Breen; Edward L. Bell; Alan Ruderman 7 ABSTRACT An adjustable needle stroke controlled needle tufting machine having means for selectively reciprocating the needles individually between an inoperative and operative position to produce patterned fabric. The machine is provided with mechanisms so that a large variation in pile height fabrics can be produced with the same machine without necessitating a complete machine conversion. The mechanism for accomplishing this comprises an adjustable needle plate, and adjustable needle stroke mechanism including an adjustable needle stop to limit the upward stroke of the needle carrier in the inoperative position.

4 Ciaims, 4 Drawing Figures [52] US. Cl. 112/79 R; 112/221 [51] Int. Cl. D05c /32 [58] Field of Search 112/79 R, 79 A, 79 FF, 112/221 [56] References Cited UNITED STATES PATENTS 2,977,905 4/1961 Cobble Sr., et al. 112/79 R 3,016,029 l/l962 Card 1 12/79 A 3,332,379 7/1967 Cobble Sr., et al ll2/79 R T -IENTEB HAY 61975 SHEET 10F 2 JONTROLLED NEEDLE TUFTING MACHINE BACKGROUND OF THE INVENTION This invention relates to multiple needle tufting machines and more particularly to a tufting machine of the controlled needle variety incorporating an adjustable needle stroke.

Controlled needle tufting machines are known which operate to skip stitch in accordance with a program for forming tufted designs in a backing fabric. Basically these machines render selective needles or groups of needles inoperative while the remainder of the needles are operative to pierce the backing fabric upon each stroke of the needle bar. Examples of this type of machine are illustrated in US. Pat. Nos. 3,115,856 and 3,259,088. However, the prior art machines have lacked versatility in that the pile height produced in the backing fabric cannot be readily varied. The controlled needle machines of the prior art are set to a single pile height, and when a fabric having another pile height is desired the needle stroke eccentrics and the needle stop bars have to be replaced. Thus, adjustment of the machine to change the pile height is time consuming and demanding. This results in large machine downtimes whenever a fabric of a different pile height is to be produced. The net effect, of course, is increased manufacturing cost of the finished product.

SUMMARY OF THE INVENTION Accordingly, the primary object of this invention is the provision in controlled needle tufting machines of a novel arrangement to simplify and facilitate adjustment of the machines to obtain desired changes in the pile height on the tufted fabric produced.

It is another object of this invention to provide a novel and improved controlled needle machine having an adjustable needle plate and an adjustable needle stroke.

The pile height in a conventional tufting machine may be adjusted by raising or lowering the needle plate and changing the stroke of the needles. The stroke changing mechanism is such as to only change the top position of the needle stroke while the bottom of the needle stroke is maintained at the same position so as not to change the relationship between the needles and the loopers and/or cutting knives. The mechanism for effecting this stroke change is similar to that disclosed in US. Pat. No. 2,977,905. In controlled needle machines, however, when a needle is rendered selectively inoperative, the needle and the needle carriers are maintained against a stop bar member in its uppermost position while the needle bar from which it is now uncoupled continues to reciprocate. When the needle is rendered operative by recoupling the needle carrier to the reciprocating needle bar. the carrier must be properly vertically positioned so as to be captured by the needle bar coupling mechanism. This invention thus proposes to selectively adjust the stop bar member so that the pile height of a controlled needle machine can be changed by changing the needle stroke.

Accordingly. a more specific object of this invention is to provide in a controlled needle tufting machine a combination of an adjustable needle plate, an adjustable needle stroke and an adjustable needle stop bar so that fabrics of different pile height can be readily produced.

Another object of this invention is to provide simultaneous adjustment of a plurality of needle stop bar support members so as to selectively vary the vertical position of the needle stop bar.

BRIEF DESCRIPTION OF THE DRAWINGS The particular features and advantages of the invention as well as other objects will become apparent from the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a vertical section taken through a tufting machine incorporating the features of the present invention; and

FIG. 2 is an enlarged elevational view of the needle portion of the machine illustrated in FIG. 1, (a) illustrating the relationship for a first pile height, (b) illustrating adjustment of the needle stop bar preparatory to increasing the pile height, and (0) illustrating the relationship of the elements for a second and higher pile height.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, and more particularly to FIG. 1, there is illustrated a tufting machine 10 of the preferred form of the invention. The machine comprises a head 12 within which is secured a plurality of collars 14, only one of which is shown, for supporting respective cylindrical sleeves l6. Journaled for reciprocation within each sleeve 16 is a push rod 18 supporting a concentric cylindrical protective shield 20 adjacent its enlarged split upper end 22. The lower end of the push rods 18 support a single needle bar 24 which extends substantially horizontally the entire length of the machine. Slidably supported for selective coupling to the needle bar are a plurality of needle carriers 26 supporting needles 28. Yarn 30 may be fed to the needles 28 in any conventional manner such as from a conventional overhead creel (not shown) through yarn guides 32 and 34 on the front of the head and guides 36 on brackets 38 secured to the needle carriers.

Below the head 12 in bed 40 are mounted a plurality of Ioopers 42 and cutters 44 which cooperate with the needles to form cut tufts in a backing fabric 46. Of course, the present invention is not limited to cut pile fabrics but is applicable to loop fabrics and cut/loop fabrics as well. Front backing fabric feed rolls 48 and 49 cooperate with rear backing fabric feed roll 50 and 51 to feed the backing fabric across a needle plate 52 for presentation to the needles and over a rear bed plate 54.

The needle plate 52 is mounted on an adjustable front bed plate 56. The bed plate 56 includes a rail 58 adapted and positioned to slide in a track 60 formed on a support member 62 forming a portion of the frame of the machine. A screw jack 64 including ajack screw 66 is supported on an angle member 68 secured to the member 62. As the bed plate 56 is preferably supported on a plurality of screw jacks, they may be interconnected one to the other by means of torque tubes 70 so that all may be raised and lowered in unison by conventional means such as a hand wheel or powered means (not shown). The needle plate thus may be raised or lowered by adjusting the vertical position of the screw jacks so as to vary the pile height of the pile produced.

The push rods 18 are driven by an adjustable drive similar to that disclosed in US. Pat. No. 2,977,905. as-

signed to the .assignee of the instant application, and to which reference can be had for a fuller description. This mechanism generally comprises a main shaft 72 rotatably mounted in pillow block bearings 74 on a cross beam 76 in the top of the head 12. For each push rod 18 there is a rock arm 78 having a split end clamped to the mainshaft. The rock arm 78 extends radially from the shaft to provide a crank arm 80 having a split end conventionally connected to a connecting link 82 by a wrist pin 84 journaled in the top of the link. A similar wrist pin 86 may connect the lower end of the link to the enlarged split upper end 22 of the push rod 18. The rocking motion of the shaft 72 thus effects a reciprocating motion to the push rods and hence the needles.

Rocking motion is supplied to the main shaft 72 through means including a cam shaft 88 mounted in the head 12 below and substantially parallel to the shaft 72 and driven at one end of the machine by conventional means. A circular eccentric cam 90 is secured preferably adjacent each end of the shaft 88 and rotates thereby. A connecting rod 92 having a lower split end section 94 is-journaled on a sleeve 96 on the eccentric cam. The upper end 98 of the connecting rod is connected in a slotted arcuate arm 100 ofa drive lever 102 secured at one end to the shaft 72. The slot 104 within the arm 100 has an arcuate path having a center of curvature coinciding with the geometric center of the eccentrically mounted cam 90 when the cam is at bottom dead center. Thus, as explained in the aforesaid U.S. Pat. No. 2,977,905, the needle stroke may be adjusted without changing the bottom position of the needle stroke. To do this merely involves repositioning a bolt 106 connecting the connecting rod 92 to the drive lever 102 within the slot 104. This change the amplitude of oscillation of the lever 102 and effects a change in amplitude of rocking of the shaft 72. The closer the bolt 106 is adjusted to the shaft 72, the greater the amplitude of oscillation and the larger the needle stroke.

As best illustrated in Figure 2A, the needle bar 24 comprises a block 108 having a plurality of substantially vertical bores 110 formed for slidably receiving the needle carriers 26, and a plurality of substantially horizontal bores 112 for slidably receiving a latch pin 114 for each needle carrier. Each needle carrier 26 has a recess 116 formed in the upper portion for receiving a detent plate 118 mounted on the top portion of the needle bar and for receiving a pointed prong 120 on one end ofthe latch pin 114. Each latch pin is pivotably connected to one end of connecting rod 122 having its other end hinged to a link 124 constrained for slidable movement in a slot 126 formed in a plate 128. A mounting bracket 130 secured to the frame of the machine 10 supports the plate 128 by means of bolts 132. A spacer member 134, through which the bolt 132 passes, located the plate 128 optimally intermediate the needle bar 124 and the mounting bracket 130. A conventional presser foot 136 is adjustably secured to the lower portion of the plate 128 by means, for example, of a screw 138 and an upstanding leg 140 of the presser foot. Vertical adjustment is provided by means of vertically elongated slots 142 formed in the leg 138.

Supported on the mounting bracket 130 are a plurality of solenoids 144, there being one for each needle. Due to space limitations the solenoids are mounted with alternate ones stepped staggered, as illustrated. The armature 145 of each solenoid is pivotably linked to one end of a connecting rod 146 which may have a conventional threaded adjustment means 147. The other end of the connecting rod 146 is hinged to the link 124. Preferably the solenoids are of the type having normally extended armatures, and upon activation are withdrawn toward the solenoid housing. Thus, when a solenoid or group of solenoids is electrically activated, the withdrawal of the armature effects a pulling on the latch pin 114 through the rods 122 and 124 and link 126 to withdraw the prong 120 from the recess 110, thereby disengaging the corresponding needle carrier 26 from the needle bar 24. When the solenoid is deactivated a spring 148 urges the prong 120 into the recess 110 so that the needle bar drives the corresponding needle carrier and needle. Activation and deactivation of the respective solenoids is controlled by a pattern control mechanism designated generally by numeral 150. Any conventional pattern control may be utilized to control the solenoids according to a pattern.

A needle carrier stop bar 152 is supported above the needle carriers to aid in limiting the upward stroke of the reciprocating needle carriers. The stop bar includes a bracket 154 to which one end of a plurality of springs 156 is secured. The other end of each spring 156 is connected to the bracket 38 secured to a respective needle carrier to urge it upward against the stop bar when the respective solenoid is activated to disengage the respective needle carrier from the needle bar. The vertical position of the stop bar should be such that when the prongs 120 of a correspondingly activated solenoid is urged towards the recess upon deactivation of the solenoids, the prongs will be properly received in the recess and will not be slammed into the needle carrier. For a fixed needle stroke controlled needle machine this is easily accomplished by fixing the stop at the upper end of the fixed stroke of the needle carrier as illustrated, for example, in U.S. Pat. No. 3,115,856. However, a fixed stop would not be effective for a variable needle stroke controlled needle machine. The present invention therefore proposes to support the stop bar by preferably a plurality of worm gear screw jacks 158 secured to the bottom of the head 112. The stop bar is secured to the screws 160 which are selectively raised and lowered by rotational actuation of a worm gear 162. A hand wheel or the like (not shown) may be used together with torque tubing to turn all the worm gear simultaneously. Calibrated indicies 164 may cooperate with a point on the hand wheel to index the stop bar by an amount substantially equal'to the change in the length of the needle stroke.

With reference to P16. 2, when it is desired to increase the pile height from that illustrated in FIG. 2A to that illustrated in FIG. 2C. the needle plate 52 is raised by means of the screw jacks 64 to the proper distance from the bottom of the needle stroke. The stop bar 152 is then raised by an amount substantially equal to the change in the needle plate by rotating the worm gear 162 of the screw jacks 158. The needle stroke is thereafter adjusted by an equal amount so as to clear the backing fabric at the top of the stroke while the bottom of the stroke remains the same. The recess 110 of the raised needle carrier is thereby positioned so that when the latch pin 114, in the now higher reciprocating needle bar 24, is returned by spring 148 from the withdrawn position of an activated solenoid to the deactivated position. the prong 120 will properly engage the recess to drive the needle downwardly. Thus, pile height adjustment of a controlled needle machine is made possible without a complete modification of the machine, thereby minimizing the amount of time wasted in converting from one pile height to another.

Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. It is to be understood that the present disclosure relates to a preferred embodiment of the invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.

Having thus set forth the nature of the invention, what is claimed herein is:

I. In a controlled needle tufting machine, means for supporting a workpiece, a needle bar, means for reciprocating said needle bar, a yarn carrying needle. means for selectively coupling said needle to said needle bar for reciprocating said needle through said workpiece, stop means spaced above said needle, means urging said needle against said stop means when not coupled to said needle bar, means spaced below said workpiece supporting means for cooperating with said needle to form pile extending from the lower face of said workpiece, means for vertically adjusting said workpiece supporting means to vary the pile height, means for vertically adjusting the stroke of the reciprocating needle bar without changing the bottom point in the stroke, and means for adjusting the vertical position of the stop means corresponding to the change in stroke of the needle bar so that the needle may be coupled to the needle bar at each adjusted stroke.

2. In a controlled needle tufting machine as recited in claim 1, wherein said stop means adjusting means comprises screw jack means supporting said stop means for vertical movement.

3. In a controlled needle tufting machine as recited in claim 1, wherein said stop means adjusting means comprises a plurality of screw jacks interconnected for simultaneous adjustment.

4. In a controlled needle tufting machine as recited in claim 1, wherein said workpiece supporting means adjusting means comprises screw jacks. 

1. In a controlled needle tufting machine, means for supporting a workpiece, a needle bar, means for reciprocating said needle bar, a yarn carrying needle, means for selectively coupling said needle to said needle bar for reciprocating said needle through said workpiece, stop means spaced above said needle, means urging said needle against said stop means when not coupled to said needle bar, means spaced below said workpiece supporting means for cooperating with said needle to form pile extending from the lower face of said workpiece, means for vertically adjusting said workpiece supporting means to vary the pile height, means for vertically adjusting the stroke of the reciprocating needle bar without changing the bottom point in the stroke, and means for adjusting the vertical position of the stop means corresponding to the change in stroke of the needle bar so that the needle may be coupled to the needle bar at each adjusted stroke.
 2. In a controlled needle tufting machine as recited in claim 1, wherein said stop means adjusting means comprises screw jack means supporting said stop means for vertical movement.
 3. In a controlled needle tufting machine as recited in claim 1, wherein said stop means adjusting means comprises a plurality of screw jacks interconnected for simultaneous adjustment.
 4. In a controlled needle tufting machine as recited in claim 1, wherein said workpiece supporting means adjusting means comprises screw jacks. 